8 Barrel Induction - HP Gains Anyone?

[rlearp]

Does anyone have any hard data on Webers or 8 barrel injection vs. 4bbl carb induction (or SB EFI)? I've seen a lot of numbers thrown around, but, does anyone have dyno sheets of the motor before Webers and after Webers with no other changes in place?

My feeling is there should be some small gain (8-15% maybe) with the indivdual runner manifold but I've not seen anyone with the real data. 1/4 times and trap speed would also work providing no other changes.

I've got a 4bbl Victor Jr and a Ford SB IDF Weber setup in the garage but the motor and are are long from done. Else I'd try it my self.

Ron

[poorboy]

Ron;
You couldn;t just change the intake system, the cams would be totaly different, and trying to match both intakes to the same set of heads would be tough. It would involve a lot more than anyone would care to do just to get some numbers.

Poorboy

[PERUCH]

Back to back comparaison between 4 IDA and 750cfm holley on victor junior manifold:
IDA
435Trq at 4700
477Hp at6400
Holley
422Trq at5300
489 Hp at 6500
Engine specs:331 cu ,10.8cr,victor Jr head 2/05.1/60 valves,mail me back for more infos,Regards,Bernie

[Jeff Frigo]

Big article in Hot Rod magazine a few months ago. Single four barrel made the most HP.

[rlearp]

From the numbers he sent me, yes a single four barrel makes the most hp.

But the torque production on the Webers is outstanding. In some cases the Webers are up 52 lb/ft and the torque is much better throughout the RPM range. Wonder what a dual plane would do with the 4 bbl?

Ron

[Mr.Fixit]

It's hard to gleam valuable data from dyno runs that were made just for a quick comparson. Properly setting up the fuel curve alone would make a HUGE difference in the achieved numbers. But in all fairness, assuming proper setup, the individual runner intake shoud make more horsepower and torque because of the lack of a venuri onthe intake. You can also manipulte the runner length more effectively take advantage of resonant tuning to your needs. Also, individual runner intakes can get more out of long duration cams according to many. I have seen the same exact motor both lose 20 hp and then later gain more tham 50 hp after individual runner efi install, as compared with a 850 holley on a victor jr on a 408windsor. The difference was the fuel management computer and program. The funny thing is it felt faster even with the lower hp numbers because the throttle was more touchy. It's much easier to pay for and setup a holley 4bbl than any individual runner intake system, carbs or injection.

[RICK LAKE]

Hi Group. Super Ford did a test in the June 1989 issue on what you want to know. I Properly tuned set of Webers will make more tork and Hp. than a carb of the same flow rating. The mid range is stronger. In the upper rpms, the single 4 barrel will win out. They make webers up to 58mm I Know of 1 motor in a cobra making over 700hp. with dyno sheets at the rear wheels. It takes a lot of time to set up the webers, choke housings, air bleeds, needles and jets. On a 452 Fe with a limit of 7000 rpms no single,dual, or 3-2 carb set up will beat the webers in mid-range tork and hp. Good luck on your setup for your car Rick Lake

[cobra427hp]

As an old guy who has run 48 IDA webers, 2X4 carters,2X4 Holleys,and various and sundry 4V carburetors, believe me nothing is as impressive as those 48 IDA downdraft carburetors! But man what a pain in the butt as far as keeping in tune. The best all around setup for me is 2X4 carbs, once you set them properly they stay set, impressive under the hood and not every body on the block has them. If you want I have some Shelby dyno test from back in the 60's where the 48 IDA produced the most HP, torque curve, and RPM range with the single Holley "R" model motor not far behind in HP, Torque,or RPM.